Best wireless router for ~$100 AUS

Hello,
I am wanting to upgrade from my single band, 300Mbp/s Belkin N300. In my home, we have my mum's laptop, my step-dad's laptop, my sisters laptop, and my gaming pc. That is for the weekdays, then on the weekends two more laptops are added to the list. At the moment, when about 3 people are on the internet, Youtube, Facebook, pretty much, everything goes spastic. My game lags, youtube videos dont load, facebook becomes un-responsive. Its terribly annoying. None of the devices at the moment support dual band 5Ghz wireless, so i dont see the point in going there, unless i decide to upgrade my network adapter. So, im looking for an ADSL2+ router, for around $100 US & or AUS. Also, my gaming computer sits about two to three walls away from the router, and (on Win7) i get usually 3 to 4 bars of connectivity.

Possible that 1 or more of the clients is hogging the bandwidth. Could be malware or P2P. Might want to check that before spending on a something you may not need.
If router is the culprit, you may get connection drops instead.